Carburetor



April 9, 1946. s. R. ERlCSON CARBURETOR Original Filed Nov. 6 1931 9 Sheets-Sheet 1 GEORGE R. ERICSON INVENTOR ATTORNEY A 9, 1946. e. R. ERICSON CARBURETOR Original Filed Nov. 6 1931 9 Sheets-Sheet 2 INVENTOR ATTORNEY 6202 a: 2- [mesa/Y April 1946- G. R. ERICSON Re. 22,742

CARBURETOR Original Filed Nov. 6 1931 9 Shee ts-Sheet E GEORGE R. ERICSON INVENTOR 4 ATTORNEY April 9, 1946. 5. R. ERICSON 9 Sheets-Sheet 4 I lull-ll l- III-Ill: /||liii GEORGE R. ERICSON INVENTOR ATTORNEY A ril 9, 1946.

Ill

(3. R. ERICSON CARBURETOR Original Filed Nov. 6 1951 9 Sheets-Sheet 5 ,1 I6 I l GEORGE R. ERiCSON INVENTOR ATTORNEY April 9, 1946. G. R. ERICSON Re. 22,

CARBURETOR Original Filed Nov. 6 1931 9 Sheets-Sheet 7 GEORGE R. ER ICSON INVENTOR ATTORNEY April 9, 1946. 5. R. ERICSON CARBURETOR Original Filed Nov. 6 1951 9 Sheets-Sheet 8 A Z 0 4 '1 I n H w a x 68 H 5 l n a m M W o o E 4 657? 6 I M F 6 6 E u M a H 7 2 4 a u GEORGE R. ERICSON INVENTOR ATTORNEY Reissues! Apr. 9, 1946 CARBUBETOB George R. Ericson, Kirlrwood, Mo., assignor to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Original No. 1,915,851, dated June 27, 1933, Serial No. 573,418, November 6, 1931. Application for reissue December 80, 1940, Serial No. 372,428

14 Claims.

This invention relates to carburetors for internal combustion engines and more particularly to thermostatic controlling devices for such carburetors. This application is a continuation in part of my co-pending application, Serial No. 446,899, flied April 24, 1930, for improvements in carburetors.

It is an object of the invention to provide a simple and easily manufactured thermostatic controlling device for varying the mixture ratio of fuel and air in accordance with the temperature.

It is a further object of the invention to produce a device of the above described character which, once adjusted, will remain constant over any period of operation.

It is a. further object of this invention to produce a device for controlling the mixture ratio of fuel and air in accordance with the suction produced by the motor.

Further objects will appear from the following description and accompanying drawings.

Referring to the drawings:

Figure 1 shows a diagram of a carburetor according to my invention applied to an internal combustion engine.

Figure LA is a diagram of the arburetor shown in Figure 1.

Figure 2 is a plan view of a larger scale of the carburetor shown in Figure 1.

Figure 3 shows a side elevation of the carburetor shown in Figures 1 and 2, with parts in section and others broken away.

Figure 4 shows a modified form of operating cylinder for use in connection with the carburetor shown in Figures 1 to 3.

Figure 5 shows a. front end elevation of the carburetor shown in Figures 1 to 3, with parts in section and others broken away.

Figure 6 is a sectional elevation of the carburetor shown in Figures 2 and 5 taken along the line 6-4 of Figure 2.

Figure 'l is a front elevation of the carburetor shown in Figures 1 to 6, with parts broken away and others shown in section.

Figure 8 is a somewhat diagrammatic elevation of a modified construction.

Figure 9 is a somewhat diagrammatic sectional elevation showing a further modification of the invention.

Figure 10 is a sectional elevation showing the invention in a further modified form.

Figure 10A is a side elevation of the device shown in Figure 10.

vatirn of the thermo-suction valve member used in connection with the device shown in Figure 10.

Figure 12 is a sectional view taken along the line l2-i2 of Figure 11.

Figure 13 is an end elevation of the device shown in Fisure 11 taken from the opposite end.

Figure 14 is an end elevation showing a modifled form of the thermo-suction valve for use in conmaction with the construction shown in Flaure 1 Figure 15 is a sectional view taken along the line iS-ll of Figure 14.

Figure 16 is a sectional view showin a further modification of thermo-suction valve for use in connection with the device shown in Figure 10.

Figure 17 shows the choke valve in partially open position and prevented from further closin by the cam ll, the thermostat being in the hot position.

Referring to the drawings, the reference numeral i indicates an internal combustion engine having an intake manifold 2, and exhaust manifold 3. The engine is provided with the usual starting device I, and storage battery 5 for operating the starting device, fuel tank 6, engine driven fuel pump 1, and connection 8 leading from the fuel tank to the fuel pump. The intake manifold 2 may have a conventional hot spot 9 for heating the mixture delivered by the carburetor. The carburetor Iii may be either of the updraft type, as shown in Figures 9 and 10, or of the downdraft type: as indicated in Figures 1 to 8.

Referring to Figures 2, 3, 5, 6, and '7, the reference numeral l I indicates a casting forming the main body member of the carburetor, and I2 is a second casting forming the top half or inlet end thereof. The carburetor is supplied with fuel from the fuel pump 1 through conduit l3 which is attached to the inlet boss M on the upper half of the carburetor, as indicated in Figure 6. Fuel is admitted to the carburetor through the needle seat It and is maintained at a constant level ,A-A in the float chamber 16 by means of needle valve I'i which is controlled by float is. A conventional vent is provided for the float chamber as indicated at 19.

The carburetor is mounted on the intake manifold by means of flange 20 at the lower end of the carburetor, and a mixture passage 2i is formed in the castings ii and I2. This mixture passage may be said to comprise a discharge outlet at the lower end of the passageway controlled by the throttle valve 22, a. main mixing chamber 23 just anterior to the throttle valve Figure 11 is a detail view showing an end eleso and below the throat of the main venturi, an air chamber 2| and air inlet II. the flow of air from the air inlet to the air chamber being controlled by a choke valve 11. The choke valve 21 may be provided with a suction operated relief valve 2| normally held in closed position by a spring for suddenly admitting a small amount of air when the motor starts to run with the choke valve in full closed position. The mixing conduit is provided with a primary venturi ti and a secondary venturi II, the primary venturi discharging near the most restricted portion of the second venturi, and secondary venturi discharging near the most restricted portion or the main venturi.

For the purpose of securing higher auctions on the primary venturi at low speeds without substantially restricting the high speed capacity of the carburetor, a venturi it may be provided at a point anterior to the main venturi 2|, so that the air stream flowing into the carburetor will be increased in velocity at the inlet of the primary venturi.

The choke valve 21 is mounted on a rotatable shaft 34 which is operated in a manner hereinafter to be described. The throttle valve 22 is mounted on a shaft 35 which is provided with a connection It, so that it may be operated by hand in any suitable manner. It will be understood that the usual hand and foot controls within reach of the driver will be used.

Fuel is supplied from the float chamber 8 to the main mixing conduit through the main metering Jet 31, through passages "-40, and main nozzle 4|. The main nozzle is disposed at an angle extending upwardly to the primary venturi ii in the manner shown in Patent #1358.- 615, granted May l'l, 1932, to G. M. Bicknell. The nozzle terminates in a recess in the wall of the primary venturi in registration with the discharge opening 42 thereof. This discharge opening is formed in a boss which is cast integral with the venturl, so that absolute accuracy in the location of the tip of the discharge nozzle is obtained. It will be understood that due to the high speed of air flowing through the primary venturi, the main nozzle is quite sensitive as to location and shape. By forming the nozzle discharge tip 2 in a die casting integral with primary venturi 3| absolute accurac is attainable in quantity production.

It will be understood that the main nozzle ll takes care of the medium and high speed range of the carburetor. In order to take care or the low speed range, an idling conduit is is formed in the wall of the casting II and provided with one or more discharge ports ll discharging adjacent the edge of the throttle valve. It will be understood that this port, if formed as a single opening, will have one portion of its discharge outlet posterior to the throttle when the throttle is in its closed position, and another part anterior to the throttle when it is in the closed position. The construction and arrangement of this port is covered in the patent to W. C. Carter #1,207.134.

If desired, the two portions of the port 44 may be formed as separate openings, one anterior to the throttle and one posterior when the throttle is in its closed position. The idle tube 3 is supplied with fuel from the passage by means of the upwardly conducted tube ll having an opening 48 therein, the tube It being connected to tube It by means of the cross passage I. This cross passage is formed Just above the fuel level in the carburetor and prevents siphoning. An air admission port 48 com trolled by adjusting screw II is provided. The adjustable admission of air at this point serves to control the richness or leanness of the idle mixture.

A metering rod 8| provided with a plurality of steps of diflerent sizes. as indicated in Figure 5, is provided for controlling the elective area of Jet 81. This metering rod is connected with the throttle shaft 3! by means of the member II, link 32, and rocker arm II. The rocker arm a is mounted on a rocker shaft 54 which is pivotally mounted to the upper half of the carburetor. An accelerating pump It in connected by means of link I to the rocker ll, so that addltional charges or fuel will be supplied upon opening movements of the throttle. These additional charges are drawn fromthe float chamher I through check valve Il during closing movements of the throttle and discharged through check valve l8 and the nozzle ll during opening movements or the throttle,

For controlling the richness of the mixture in accordance with the temperature and operating condition of the motor, a cylinder II having an inlet 82 for operating fluid is provided. The operating fluid is supplied from a pump which is operated by the engine. This pump ma be specially provided for the purpose. but in this case I use the fuel pump 1 and connect it to the inlet 62 by means of conduit 3, as indicated in Figure 1.

A check valve '4 having a small oriflce it therein is held in place in the inlet by a spring 88, so that the fluid will be admitted to the cylinder II at a slow rate, but permitting it to be discharged much more rapidly. A piston 81 provided with the usual packing is mounted in cylinder ti. and a spring is held in position by the combination cover and guide member In is provided for normally holding the piston 61 in its downward position. The piston 61 i provided with a piston rod ll slidably mounted in the cover l8 and connected by means of link I2 and operating arm II to the choke shaft 3|.

The connection is made by means of suitable ball and socket or pivot joints ii and It. The arm 13 is so mounted on shaft ll as to close the choke when the piston 81 is in its downward position, and the choke valve will he opened by an upward movement of the piston 81. The motion of the arm 13 is controlled by a double cam comprising segments 18 and I1 formed in a single piece and pivotally mounted to the upper half of the carburetor at It.

The cam is controlled by a thermostat or heat responsive element III. This heat responsive element may be of any type, but I have shown in Figures 1 to 3 a coil of the conventional bimetallic form mounted on a flxed pivot BI and having its outer end connected by means of link 82 to the operating arm I3 oi the double cam member.

The choke operating arm I3 is provided with a pair of rollers 84 for contacting with the cam surfaces I6 and I1. so that the opening and closing movements of the choke will be limited by the cams.

In Figure 4, I have shown a modified form of operating cylinder to replace the cylinder i and its associated parts. The diflerence is chiefly in the use of a diaphragm 85 in place of the plunger 81 and the change in form of the cylinder t provide a diaphragm housing I.

The operation of the device shown in Figures 1 to 7 is as follows:

saw: 3

Wnenthelnotorisnot and when the thethermostatllwillwithdrawthecam II from temperature is low. the thermostat 8| contracts in the path of the rollers 84 and permit the gradual an anti-clockwise direction with reference to Plgclosing of the choke valve in accordance with the ure 5, drawing the member 88 downwardly and degree to which the cosine has cooled oil, so that removing the cam I! from the path of the rollers s the starting and warming up operation man be I in accordance with the degree to which the temperature is lowered. If the temperature is lowered to a sumcient extent, the cam II will permit rotation of the operating arm 13 in an anticlockwise direction with reference to Figure 3. so as to fully close the choke valve 21. This movement is caused by the spring II.

when the engine is started under such conditions the fuel pump produces a substantial pressure amounting to approximately three or four pounds per square inch on the lower side of the piston 61. This pressure, however, is not produced at the cranking speed of 80 to 100 R. P. M., because the choke valve is in closed position and the suction on the nozzle I and port 44 is high enough to withdraw fuel at a very rapid rate. For that reason, the fuel pump is prevented from building up its normal pressure.

When the en ine starts to run under its own power, the rate of fuel delivered by the fuel pump is increased. and the resulting pressure also increases to a point at which the piston 81 or diaphragm 85 may be operated. The piston or diaphragm then begins a gradual opening movement of the choke valve.

At the first fire of the engine, the suction is increased from approximately A pound per square inch to several pounds per square inch, and the relief valve 28 is opened. thereby admitting sufllcient air to operate the engine at several hundred R. P. M. in spite of the resistance of the cold oil on the cylinder walls.

While the thermostat II has been shown as being mounted on a part of the carburetor, it will be understood that the thermostat is intended to be exposed to at least some degree of heat, and this thermostat may if desired be mounted on the exhaust pipe or on the hot spot of the inlet manifold as indicated in Figure 9. Where the carburetor itself is sufllciently heated, I prefer to mount the thermostat as shown in Figures 2, 3. and 5, but the location of the thermostat will be selected according to the heat characteristics of each particular type of installation, and artificial heat may be provided if necessary.

As the engine continues in operation, the piston 61 will be raised until the roller 84 contacts with the cam 18, so that the choke valve 21 will be brought to a position in which it will admit some air almost immediately when the motor starts to run, but the amount of air admitted will be varied in accordance with the operating temperature. As the thermostat III warms up, the cam 16 will be moved downwardly, and the pump pressure will cause the piston 81 to rise and open the choke valve as fast as such opening is permitted by cam I6. When the cosine reaches normal operating temperature, the limit of movement of the choke valve will be reached, and the valve will remain in that position as long as the engine is running.

When the engine is stopped, the fuel in conduit 63 will no longer be under pressure, and the spring ill will return the piston 01 toward the lower end of its stroke, thereby closing the choke valve 21. If the engine is hot, however, the choke valve will not be permitted to return to its full closed position. The upper one of the rollers 84 starting from the position shown in Figure 17 will contact with the cam II. and further movement thereof will be arrested. As the engine cools oil.

repeated as hereinbefore described.

It should be understood that I may, in some installations, provide a substantial amount of lost motion between the rollers 04 and the cams 1| and 11. This lost motion will amount to 20 or 30 degrees in movement of the choke valve 21, and the purpose is as follows: It ordinarily requires a richer mixture to start an engine than to keep it running, and the cranking speed is considerably below the operating speed. The low cranking speed does not pull over as much fuel in comparison with the amount of air as would be pulled over at a higher speed. For that reason. it is desirable to have a slight restriction of the air inlet under starting conditions and to eliminate that restriction as soon as the engine starts. provided lost motion between the rollers 84 and the cams l6 and TI accomplishes that object in a very convenient manner.

A third form of my invention is shown in Figure 8. In this embodiment, the operating cylinder II is operated by the suction developed in the intake manifold of the engine. The intake manifold is indicated in Figure 8 by the reference numeral 2 and is connected with the upper end of cylinder 81 by conduit ll which is controlled by a regulating screw it. The piston ii is, of course, modified so that it will be operated by auction, but it should be noted that either a piston provided with a leather packing or a solid metal piston with no packing may be used. The leaking in the solid metal type is not of great importance, as a substantial amount of air may ordinarily be admitted to the intake manifold without upsetting the mixture ratio. An inlet opening 82 is provided at the lower end of cylinder 81, so that the lower side of the plunger will be exposed to atmosphere. The remaining parts of the carburetor are the same as shown in Figures l to 7.

The operation of the device shown in Figure 8 is the same in principle as that of the device shown in the preceding figures, except that the increased suction produced by the engine beginning to operate under its own power provides the force for opening the choke valve. In both movements, however, the motive force is derived from a fluid pressure which is set up by the operation of the engine when it is running under its own power.

A further embodiment of the invention is shown in Figure 9. In this figure, the carburetor is of the updraft type and the reference numeral lfli indicated a main body casting having an air horn or air inlet ill therein. This air horn leads into an air chamber ill which discharges through a venturi Ill formed in a second body member I which is attached to the first body member by suitable screws ill, the body member III is provided with a flange It! by means of which it is attached to the inlet manifold of an internal combustion engine in the usual manner.

A throttle valve ill mounted on a'sllltable shaft Ill! is provided for controlling the outlet of the carburetor. The body member ill is provided with a downward extension I I! surrounded by an annular seat ill, a cup-ahaped howi H2 is seated at its rim on the annulariseat ill and retained in position by a nut I I3 which is threaded into the lower end of the extension III.

Fuel is supplied to the bowl by any suitable means, such as an engine driven pump or a vacuum tank, and it is maintained in the bowl at substantially the level A-A by a conventional float mechanism III. A conventional bowl vent I30 is provided, as indicated in Figure 10A. The inlet connection and the float valve are not shown, these being so well known in the art that no further description is necessary.

A standpipe H3 is threaded into the lower portion of the air chamber as shown. Ports II3 are provided in the lower portion of the standpipe to receive air from the air chamber III. A restricted throat III if formed in the standpipe above the entrance of the air inlet for the purpose of increasing the air speed at the point to insure thorough vaporization of the fuel. An air bleed H8 is drilled in the lower portion of the standpipe and communicates with the well I I! formed in the extension IIO of the body member I I. The well II! is provided with screw threads I20 at its lower portion to receive the corresponding threads of the nut H3 and also to receive the threads of a nozzle I2I which is mounted conoentrlcally with the well II3 extending from the lower portion of this well to the restricted portion II! of the standpipe.

Accelerating holes I22 are provided for the nozzle and form a communication between the well II! and theanterior of the nozzle. Fuel is supplied to the well H3 and to the interior of the nozzle through suitable passages I22 and I23, respectively, which form communication between the well and nozzle and the space between the nozzle and the end of the nut H3, as indicated at I24.

A cross connection I23 supplies fuel to the lower end of the idling tube I23 and the fuel enters this tube through the small port I21, as shown. Conventional air bleeds I23 are provided in the idle tube above the fuel level, and the upper end of the tube is connected to a bore I23 in the body member I03. From this bore the fuel passes to an outlet port I23 in the side of the outlet passageway I30 01' the carburetor.

This port is formed at the point where the throttle valve closes against the side of the passageway, and when the throttle is slightly open, as it is when adjusted for proper idling, at least a portion of the port I23 is in communication with the mixing conduit at a point posterior to the throttle. In this manner a suction connection from a point posterior to the throttle is provided for admitting the idling fuel and for affecting the valve.

When the engine is operating under its own power but at low speeds, for instance, with the throttle one-eighth open, the port I23 would be fully exposed to the suction above the throttle and that suction will be very high, perhaps corresponding to 7 or 8 pounds per square inch. Excellent vaporization of the gasoline is accordingly obtained, and it is therefore desirable to lean out the mixture to a certain extent. The suction connection comprising port I23, passages I23, I33, and I33 transmit the suction from above the throttle to the valve I42 causing it to close or partly close, and thereby lean out the mixture.

A transverse threaded bore I3I is formed in the extension IIO near the lower end of the carburetor, and a body member I32 is threaded into this bore. Body member I32 comprises a large passageway Ill calibrated to meter the maximum quantity of fuel, which it is desired to pass through the carburetor under low temperature conditions, opening into a threaded bore I34 which receives he screw threaded ends of a second body member I33 having a longitudinal bore I33 01 comparatively large diameter, so that it does not form a restriction or calibration, and

a small calibrated longitudinal bore I31 of considerably smaller diameter than the bore I33, a transverse bore I33 of larger diameter than the bore I31 is drilled in the body member I23 and provides the main communication between the bore I33 andthe fuel in the bowl.

A bracket I33 having a. perforation I40 is attached to the two body members by screwing them together, the perforation I40 surrounding the threaded end of the body member I33. The bracket is bent into a U shape at the end opposite the perforation I40 to provide a parallel short leg I to which may be attached the thermally operated controlling member I42. This control member is formed of a straight flat piece of the usual bimetallic thermostatic material, the more expansible metal being placed on the outside, and the less expansible metal being placed next to the end of the body member I35. The member I42 is held in place by any suitable means. such as a rivet I43. It will be understood that the member I33 may be inserted or withdrawn from the U-shaped bracket by swinging the member I42 on the pivot I43. When the member I42 is swung aside, the member I33 may also be readily engaged by a wrench.

The passageway I33 is so calibrated that when the temperature is reasonably high say, above '70 degrees Fahrenheit, in the fuel bowl of the carburetor, the combined resistance offered by the passageways I22, I23, and I33 regulate the flow of fuel to give a proper mixture for operating under high temperature conditions. It will be understood that the control member I42 moves to the left of the Figure 3 and closes when the temperature is in excess of approximately degrees Fahrenheit, thereby closing the opening I31 and causing all the fuel for the carburetor to flow through the passageway I33. When the temperature falls below '70 degrees Fahrenheit in the fuel bowl, the member I42 moves to the right, opening the passageway I31, thereby enriching the fuel mixture by the capacity of the passage I31 which is approximately one-eighth of that of the passage I33. The fuel is then metered at the passage I33 and at the passages I22 and I23.

A feature of this invention is that the thermostatic metal is made comparatively short, but very thin, and flexible by mechanical force as well as by changes in temperature, and this has a very important object in this invention, in addition to securing the great cheapness and simplicity of construction which are also obtainable with this device.

In cold weather, when the automobile to which the carburetor is attached is operated continuously at low speed, the fuel in the carburetor bowl will reach a temperature of approximately 70 degrees or more without very great delay; for instance, when the outside temperature is zero, the carburetor bowl will probably attain a temperature of '70 degrees within about three to five miles, but if the car is driven at high speed, for instance. in excess of 40 miles an hour, the rate of fuel flowing into the bowl is so rapid that the temperature existing in the bowl is likely to approach that existing in the fuel tank and not that of the engine. The fuel tank is ordinarily mounted at the rear end of the car and is very likely to be cold, and the rate of heat conduction down through the body of the carburetor being substantially constant, a rapid lowering of the temperature in the bowl is experienced, with the result that one would expect the thermostat to open up and give an undesirably rich mixture while driving the car at high speed in cold weather. This difiiculty is overcome in my device by the following construction:

The thermally controlled element I42 is made very thin, say, in the order of .017 of an inch in total thickness of the two metals, and the length and width and thickness are so selected with respect to the suction of the carburetor that the suction at the end of the bore I 81 at speeds above 40 miles an hour will bend the member I42 into contact with the face of the member Ill, closing the here I". It will be understood that greater thicknesses of thermostat metal could be used with greater length, or less width, or greater areas exposed to suction, etc.

By reason of the fact that at speeds of 40 miles an hour or more, the fuel is thoroughly vaporized by the comparatively high air speed, it is unnecessary at such speeds to supply additional fuel even if the temperature is low. This condition is also partly due to the fact that the temperature in the bowl at speeds of 40 miles an hour or more is likely to be much lower than that of the engine itself.

A choke cone I44 is slidably mounted on the standpipe Ill and is operable by a 'yoke I45 mounted on an arm I48 for the purpose of restricting or cutting off the annular passage I41 between the upper end of the standpipe III and the throat of the venturi I04. This arrangement is used for starting or for extreme cold weather conditions, as desired.

The valve or choke cone I44 corresponds to the choke valve 21 in the preceding modifications. The shaft I also corresponds to the choke shaft 34 in the preceding modifications, and the same operating devices for operating choke valve I44 in accordance with the temperature and .suction of the engine may be provided. The fuel pump pressure may also be used to control the choke valve I44.

In the embodiment shown in Figure 9, the heat and suction for operating the choke valve are applied as follows: A diaphragm housing comprising an upper half IIII and a lower half ISI is mounted on the lower part of the carburetor, as indicated. The diaphragm I52 normally held in its lower position by spring I" is mounted in the housing and connected by shaft I54, link I", and arm lit to the choke shaft I44. The upper half I50 of the housing is connected by means of the conduit I" to a point in the discharge outlet I30 of the carburetor.

The exhaust pipe 3 is provided with an opening I58 surrounded by boss I! to which is attached a member I80 having a chamber IGI therein to contain a vaporizable fluid such as ether or the like. This chamber is of comparatively small capacity and is connected by means of conduit I52 to the lower half of housing Ill. The amount of ether in chamber IBI is comparatively small and is quickly vaporized upon the starting of the engine and the resultant heating of the exhaust pipe I. The liquid used in chamber IOI is preferably so selected that it may be at least partially condensed at the temperatures to which the chamber III is subjected andatpressures below 100 pounds per square inch, so that excessive strains on the diaphragm and leakage may be avoided.

The operation of the device shown In Figure 9 is as follows:

The carburetor being attached by means at flange IIII to an internal combustion engine, air enters the air inlet I02 and flows through port I IS in the base of the standpipe up past the nozzle and through the restriction III in the standpipe and into the main venturi or mixing chamber I04. Air from the inlet I02 also passes through the air chamber III! and flows through the annular space I41 around the top of the standpipe. Fuel being supplied to the bowl and maintained at a constant level AA, the suction caused by the operation of the engine draws fuel into the passageway I38 through the bores I38, I33, I22, and I23 into the nozzle and the accelerating well IIQ.

Air from the air chamber flows down through the air bleed I08 and mixes with the fuel in the nozzle and the accelerating well, passing up through the discharge outlet of the nozzle into the primary mixing chamber I48 above the restriction H1 in the standpipe.

When the carburetor is operated under high temperature conditions, for instance, about 70 degrees Fahrenheit, the thermally controlled element I42 will be bent to the left to close the end of the passage I31 so that all the fuel must pass through the passageway Ill, thereby providing a mixture which is calibrated for high temperature operation.

85 When the temperature is low, as when starting up on a cold morning, the thermally controlled element I42 is bent to the right as shown in Fig ures 1 and 3 to permit additional fuel to enter the passageway and thereby enrich the mixture in the degree of approximately 12 per cent. When the choke valve I44 is closed and the throttle slightly opened, as for starting at low temperature, the suction is built up at higher than normal for the same operating speed by the fact that the choke valve is closed, preventing the relief of suction by air entering at I41. When the engine is cranked at normal cranking speeds, say, from 40 to R. P. M., the suction developed at such low speeds is not sufficient to close the valve I42 if the temperature is extremely low-for instance, zero Fahrenheit, or below. However, when the engine starts to run under its own power,-the suction is substantially built up due to the increase in operating speed of the engine to anywhere from 200 to 400 R. P. M.

The high suction which will now be built up by the engine is communicated to the valve I42 which closes and leans out the mixture, and in this manner a member is provided for leaning out the mixture as soon as the engine starts to run under its own power. When the valve I44 is opened, the suction is again decreased, and if the temperature is low and the speed not above normal, the valve I42 will again be open in response to the' lowered suction. It will be noted that the port I29 is posterior to the throttle valve when thatvalve is slightly open and the port is also posterior to the choke valve I44, so that the suction conveyed to the valve I42 may be responsive to movements of either the throttle or choke valve, and the claims should be construed accordingly.

When the engine reaches normal operating temperature, heat from the engine is conducted down through the body to the carburetor and the ex ension I"! to the fuel in the bowl, thereby warming the fuel in the bowl and the thermally controlled element I42 which thereupon bends to the left and closes the end of the orifice I81.

When the fuel in the main fuel tank is very cold and the car is operated at high speed, the temperature in the bowl will again fall, due to the rapid rate of flow of the cold fuel into the bowl. This, however, will not cause the thermally controlled element It! to open the end of the passageway I81, except under extreme cold conditions, because the suction will hold the member I42 in closed position.

During starting, the diaphragm I52 will be in its lower position, thereby closing choke valve I 44. However, if the temperature is high, the fluid in chamber IBI will be partially vaporized and the choke will not be permitted to close the full distance. If the choke is fully closed, the concentration of suction upon the fuel jet IlI will cause the valve I42 to close by suction as soon as the engine is cranked, thus restricting the passage I31 and having a tendency to lean out the fuel mixture and permitting the use of higher suctions to assist in vaporizing the cold fuel without danger of overloading the engine with fuel during cranking.

Additional leaning out is desired as soon as the speed of the engine is increased from cranking speed to operating speed, and a relief valve may be mounted in the choke valve III, said relief valve to correspond to valve 28, shown in Figure 5. The action of such a relief. valve will, of course, add to the leaning out effect of the closing by suction of valve I42. It will be understood that the cranking or running speed at which valve I42 will close by suction will depend on the temperature.

When the engine begins to operate under its own power, the suction from above the throttle will be applied to chamber I50 through conduit I51, and the diaphragm in will be raised against the pressure of spring I53, thereby causing the choke to be opened. The strength of the spring I53 is so selected that suction in chamber IIII is not alone suillcient to move the choke valve to full open position when the temperature is low, but the normal graduating effect of the spring I! will cause a stoppage of the operating movement of the diaphragm at a point which will vary in accordance with the suction derived from chamber I30, and the pressure derived from chamber IGI, and conduit I82. In this manner, the choke valve will at first partially open, then gradually be fully opened as the engine warms up.

With reference to the device shown in Figures 10 to 13, this carburetor is the same in principle and operation as the device shown in Figure 9. with the exception that the thermo-suction control affects the fuel supply alone, the valve I being manually operated, and the thermo-suction control device for shaft I is omitted. The construction and operation will be fully understood from the preceding description.

With reference to the device shown in Figures 14 and 15, the main Jet member I'll is used to replace the jet Ill-III, as shown in Figure 9. Instead of having an additional orifice I38 for the lean carburetion, I provide orifice III in the thermostatic valve "2. Such provision may be -formed by a punching operation, and the necessity of drilling the additional pasageway in member III) is eliminated. A bracket I'll corresponding to bracket I" is provided for supporting the thermostatic valve.

with reference to the device shown in Figure 16, this is a slight improvement on the construction shown in Figures 14 and 15 in that the orifice III is carried in a member I'll which is mounted in a ball and socket Joint on the thermostatic member I18. At the end of the member ill, a ball-shaped discharge outlet I" is provided to contact with the re-entrant surface of the Jet member I". The ball and socket joint permits free movement within limitations of the member I" in the thermostat I", so that absolute registration of the orifice III with the passageway through Jet I" is unimportant.

I have shown in Figure 6 a construction by which the discharge of the accelerating pump may be controlled in accordance with the temperature. This construction embodies a thermostat member IBI pivotally connected to the rock shaft 54 and also to the upper connecting pin I82 of the link It. This thermostat is of the usual bimetallic form with the same expansible metal on the outside of the loop I" so as to shorten the operating arm between shaft II and pin I82 when the temperature is high. This construction, however, is not claimed in this application, but will be claimed in a division thereof.

I claim:

1. In a plain tube carburetor, means forming a mixing conduit, means forming a constant level fuel chamber, means comprising a fuel conduit for delivering fuel from said constant level chamber to said mixing conduit, a throttle valve controlling the flow of mixture from said carburetor, said fuel conduit comprising an inlet branch and a pair of discharge branches. one of said branches discharging adjacent said throttle valve, and the other discharging anterior to said throttle valve, means comprising an air inlet for admitting air to said mixing conduit, said fuel and air inlets during high temperature and normal operation of the carburetor being of constant size regardless of either temperature or the suction which may be applied to said carburetor, a valve for controlling one of said inlets, and means responsive to both suction and temperature for controlling said valve, stop means for said valve, to limit its movement as the temperature reaches normal,

said valve being unaflected by suction after it comes in contact with said stop.

2. In a carburetor, means forming a mixing conduit, means forming a constant level fuel chamber, said mixing conduit having a discharge outlet, 8. throttle controlling said outlet, a venturi in said conduit anterior to said throttle, a fuel conduit having an inlet branch and two outlet branches, one of said outlet branches discharging near the throat of said venturi, and the other of said outlet branches discharging adjacent said throttle, an air inlet for said mixing chamber. means comprising a plurality of openings located at different levels for admitting corrective air from said air inlet to that branch which discharges near the throat of the venturi, said air inlet and the inlet branch of said fuel conduit being normally open and of constant size regardless of either temperature or suction after the temperature has reached a predetermined minimum, whereby the flow characteristics of said carburetor will be controlled by said throttle and said corrective air, and means for controlling one of said inlets comprising a suction and temperature operated valve, said valve acting to enrich the fuel mixture at subnormal temperature and low suction and also acting either by increased temperature or increased suction or both to lean out the mixture to the normal operating condition thereof.

3. In a carburetor. means forming a mixing conduit, said mixing conduit having a mixture outlet, an air inlet and an air chamber between said inlet and outlet, a manually operable valve between said air chamber and said outlet. means forming a fuel supply conduit, means for admitting air to said fuel conduit from said air chamber, valve means for controlling the richness of the mixture delivered by said carburetor, means responsive to both-heat and suction for operating said valve to lean out the mixture at high temperatures and suctions and enrich said mixture at low temperatures and suctions, and a suction connection leading from a point in said mixing conduit posterior to said first-named valve for operating said mixture controlling valve.

4. In a plain tube carburetor, means formin a mixing conduit, said conduit having an air inlet and a mixture outlet, means forming a fuel supply chamber, a branched conduit having a single inlet anda plurality of outlets, said inlet communicating with said fuel chamber to receive fuel therefrom, and said outlets discharging at spaced points in said mixing conduit, a throttle valve in said mixing conduit, said throttle valve being posterior to one of said fuel outlets but adjacent the other of said fuel outlets, a suction operated valve for controlling the flow of fuel to said branched conduit, said valve beingmounted in and operated in the closing direction by the suction applied to the liquid fuel.

5. In a carburetor, means forming a mixing conduit, said conduit including an air inlet, a fuel inlet, and a mixture outlet, a manually operated valve for said conduit, a valve for controlling the iiow through one of said inlets to enrich or lean out the fuel mixture discharged by said carburetor, a heat responsive device capable of operation independent of suction for operating said valve in accordance with the temperature to lean out the mixture upon an increase of temperature, and means for operating said valve to lean out said mixture upon an increase in suction in the carburetor, said last-named means including a suction conduit connected to a point in the mixing conduit posterior to said manually operated valve, said heat responsive device being constructed and arranged to allow said valve to move to its leanest position when the normal operating temperature is reached or exceeded, and to remain in such position as long as said normal operating temperature is maintained or exceeded regardless of suction.

6. In a carburetor, means forming a mixing conduit, a throttle valve controlling the flow of mixture through said conduit, means forming a constant level fuel supply chamber, a fuel conduit leading from said fuel supply chamber and having a main outlet into said mixing conduit at a point anterior to said throttle, said fuel conduit having a low speed branch, said low speed branch having an outletin the wall of said mixing conduit, said outlet being located near said throttle valve when it is in closed position, said fuel conduit having an inlet located below the fuel level in said constant level fuel chamber, aid mixing conduit having an air inlet, a valve in one or said V conduit, a throttle valve controlling the flow of mixture through said conduit means forming a constant level fuel supply chamber, a fuel conduit leadingfrom said fuel supp chamber and a' maih outlet into said mixing conduit at a point anterior to said throttle, said fuel conduit having a low speed branch, said low speed branch having an outlet discharging in the wall of said mixing conduit, said outlet being located near the edge of said throttle valve when it is in closed position, said fuel conduit having a fuel inlet and said mixing conduit having an air inlet, valve means for controlling one of said inlets, said valve being operable to vary the proportions of fuel and air delivered by said carburetor, and means responsive to both temperature and suction for operating said valve to mixture enriching position when both the suction and the temperature are low, and for operating said valve in an opposite direction to lean out' aid mixture when either the temperature or the suction increases.

8. In a plain tube carburetor, means forming a mixing conduit, an air inlet and fuel inlet for said mixing conduit. said air and fuel inlets being or constant size regardless of suction under normal operating conditions. and valve .means for controlling at least one of said inlets in accordance with both temperature and suction for starting purposes when the operating temperature is below normal.

9. In a plain tube carburetor, means forming a mixing conduit, air and fuel inlets for said conduit, both of said inlets being of constant size regardless of suction to give a constant fuel mixture ratio during normal operation, valve means for controlling each of said inlets to enrich the fuel mixture ratio under abnormal operating conditions, one of said valves being responsive to suction and being operable by suction to move it to the normal operating position, and one of said valves being operated in response to temperature changes whereby it will be moved to its normal operating position when the temperature reaches normal.

10. In aplain tube carburetor, means forming a mixing conduit, and air inlet and fuel inlet for said mixing conduit. said air and fuel inlets being of constant size regardless of suction and adapted to deliver a constant fuel mixture ratio under normal operating conditions, a valve for controlling one of said inlets to enrich the mixture whenever the temperatur is below normal, heat responsive means for operating said valve, said valve being constructed and arranged to be directly acted on by suction, when it is in mixture enriching position, and being displaced by suction in a direction to cause a leaner mixture to be delivered by the carburetor.

11. In a plain tube carburetor, means forming a mixing conduit, air and fuel inlets for said mixing conduit, said inlets being of constant size regardless of suction to deliver a constant fuel mixture ratio whenever the temperature is at or above normal, means controlling one of said inlets to enrich the mixture when the temperature is below normal, said means comprising a, valve constructed and arranged to be directly acted on by suction and to be moved by suction in a direction to lean out the mixture to normal proportions, means to limit the movement of the valve in that direction, and thereby determine the normal operating position of the valve, and heat responsive means to move the valve to its normal position independent of suction.

12. In a plain tube carburetor, means forming a mixing conduit, said conduit including a main air inlet, a main fuel inlet, and a mixture outlet,

a manually Operated valve ior said conduit. a valve for controlling the flow through one or said inlets to enrich or loan out the fuel mixture discharged by said carburetor, a heat responsive device capable of operation independent oi suction for operating said valve in accordance with the temperature to lean out the mixture upon an in crease of temperature, and means for operating said valve to lean out said mixture upon an increase in suction in the carburetor. said lastnamed means including a suction conduit connected to a point in the mixing conduit posterior to said manually operated valve, said air and fuel inlets being of constant size regardless of suction during operation oi the engine at normal temperature.

18. In a plain tube carburetor, means forming a mixing conduit, said conduit including a main air inlet, a main fuel inlet. and a mixture outlet,

a manually operated throttle valve for said con- 20 unit, a valve for controlling the flow through one of said inlets to enrich or lean out the fuel mixture discharged by said carburetor, a heat responsive device for controlling said valve in accordance with the temperature to lean out the mixture upon anincrease of temperature, said heat responsive device being constructed and arranged to operate said valve onl when the temperature is below normal, and means for operating said valve to lean out said mixture upon an increase in suction in the carburetor, said lastnamed means including a suction conduit connected to a point in the mixing conduit posterior to said manually operated valve, and meananior temporarily enriching the mixture delivered by said carburetor regardless of temperature.

14. In a carburetor, means forming a mixing conduit, said conduit including a main air inlet. a main fuel inlet, and a mixture outlet, a manually operated throttle valveior said conduit. an inlet valve for controlling the iiow through one of said inlets to enrich or lean out the fuel mixture discharged by said carburetor, a heat responsive device for controlling said valve in accordance with the temperature to lean out the mixture upon an increase of temperature, said heat responsive device being constructed and arranged to operate said valve only when the temperature is below normal, and means for operating said valve to lean out said mixture upon an increase in suction in the carburetor. said last-named means including a suction conduit connected to a point in the mixing conduit posterior to said manually operated valve, and means for temporarily enriching the mixture delivered by said carburetor upon 'an opening movement of said throttle, regardless of the position of said inlet valve.

GEORGE R. ERICSON.

Disclaimer Re. 22,742.-George R. Eflcson, Kirkwood, Mo. CARBURETOR. Patent dated Apr. 9, 1946. Disclaimer filed Nov. 8, 1950, by the assignee, Garter Carburetor Corporation.

Hereby enters this disclaimer to claim 14 of said patent.

[Officz'al Gazette December 5, 1950.] 

